Facebook hailed a new era in energy-efficient computer processing as it opened a vast server warehouse on the edge of the Arctic Circle in northern Sweden for its 350 million European users.

The social network’s first server facility outside of the United States will fall under Swedish internet and privacy laws, the company said, although the data will all be duplicated in the US.

While Facebook was keen to talk about the use of renewable energy to power the 28,000 square metre centre, it refused to answer further questions about the capture of data by the US authorities under their